How Could You Repay the Kindness I Raised You With Obsession? - Chapter 25

This chapter only further makes my suspicions seem likely, but even wilder theory about how FL ended up here:

The witch who has already done soul transference magic switch their souls (this is seemingly the obvious thing they want us to think), but she did it to bring in someone who could properly love the children that she left parentless since she couldn’t (?) do it herself.